Electronic displays and more specifically liquid crystal displays typically require some type of light source in order to generate an image upon a viewable screen. Specifically for liquid crystal displays (LCD's), a light source is required to shine through the crystals, where the crystals control the amount of light which will pass through by orienting themselves in response to a potential difference. This light source is typically referred to as the Back Light Unit (BLU), as this light source is placed behind the crystals and towards the back of the display assembly.
Previously, an arrangement of fluorescent lights has been used to construct the BLU for LCDs. Energy, environmental, relative size, life span, and various other concerns have prompted the electronic display industry to seek different lighting structures to produce the backlight for displays. A BLU for an LCD display which is comprised of various arrays of LEDs is disclosed in U.S. Pat. No. 7,052,152 and is herein incorporated by reference in its entirety.
For illustrative purposes, LED backlights may be discussed, but the embodiments may be practiced with any one of the following: LEDs, organic light emitting diodes (OLED), field emitting display (FED), light emitting polymer (LEP), and organic electro-luminescence (OEL).
LEDs have a limited life span, and eventually their luminance will degrade until little or no luminance is generated. Some LEDs may quickly fail simply due to a manufacturing defect. Currently when this occurs in an LED backlight, the entire BLU assembly is replaced (i.e. the element which every LED is mounted to is replaced with a new element containing all new LEDs). This is expensive, and is an unnecessary waste of the good LEDs which remain in the backlight. Alternatively, the LED backlight assembly could be removed from the display housing, and the degraded or faulty LEDs could be manually replaced. This is typically even more costly, and involves extensive manual labor. In currently known units, this also requires virtual complete disassembly of the LCD to gain access to the BLU. This complete disassembly is not only labor intensive, but must be performed in a clean room environment and involves the handling of relatively expensive, delicate, and fragile components that can be easily danger or destroyed, even with the use of expensive specialized tools, equipment, fixtures, and facilities.
These problems are intensified as the modern electronic displays, and more specifically LCDs grow larger and larger. For large displays, replacing the entire LED backlight assembly could be extremely expensive and could waste a large number of LEDs which still work properly, as well as damage or destroy the fragile LCD itself.